Utility companies fell as investors wait for a decision on whether the Tiwai Point aluminium smelter, which uses a seventh of the country's energy and is contracted to Meridian Energy, will remain open or seek to change its power arrangements.

Owner New Zealand Aluminium Smelters was due to make a decision at the start of July, but has since pushed that out until early August.

Meridian led the benchmark index lower, down three percent to $2.075.

Mighty River Power declined 0.4 percent to $2.825 and Genesis Energy fell 0.3 percent to $1.695.

"I think that is weighing on it a little bit," said Grant Williamson, director at Hamilton Hindin Greene.

He said there was also continuing nervousness over the Greek debt crisis and Chinese stock markets so investors have taken some profits.